package com.leo.book.netty.chapter02;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;

public class NIOTimeClient {
	
	public static void main(String[] args) throws IOException {
		int port = 8080;
		if (args!=null && args.length>0) {
			try {
				port = Integer.valueOf(args[0]);
			} catch (NumberFormatException e) {
				//
			}
		}
		new Thread(new TimeClientHandle("127.0.0.1", port), "TimeClient-001").start();
	}
	
}

class TimeClientHandle implements Runnable {
	private String host;
	private int port;
	private Selector selector;
	private SocketChannel socketChannel;
	private volatile boolean stop;
	
	public TimeClientHandle(String host, int port){
		this.host = host==null?"127.0.0.1":host;
		this.port = port;
		try{
			selector = Selector.open();
			socketChannel = SocketChannel.open();
			socketChannel.configureBlocking(false);
		}catch(IOException e){
			e.printStackTrace();
			System.exit(1);
		}
	}
	
	@Override
	public void run() {
		try{
			doConnect();
		}catch(IOException e){
			e.printStackTrace();
			System.exit(1);
		}
		while(!stop) {
			try{
				selector.select(1000);
				Set<SelectionKey> selectedKeys = selector.selectedKeys();
				Iterator<SelectionKey> it = selectedKeys.iterator();
				SelectionKey key = null;
				while(it.hasNext()){
					key = it.next();
					it.remove();
					try{
						handleInput(key);
					}catch(Exception e){
						if(key!=null){
							key.cancel();
							if(key.channel()!=null)
								key.channel().close();
						}
					}
				}
			}catch(Exception e){
				e.printStackTrace();
				System.exit(1);
			}
		}
		if(selector!=null){
			try{
				selector.close();
			}catch(IOException e){
				e.printStackTrace();
			}
		}
	}

	private void handleInput(SelectionKey key) throws IOException {
		if(key.isValid()){
			SocketChannel sc = (SocketChannel)key.channel();
			if(key.isConnectable()){
				if(sc.finishConnect()){
					sc.register(selector, SelectionKey.OP_READ);
					doWrite(sc);
				} else {
					System.exit(1);
				}
			}
			if(key.isReadable()){
				ByteBuffer readBuffer = ByteBuffer.allocate(1024);
				int readBytes = sc.read(readBuffer);
				if(readBytes>0){
					readBuffer.flip();
					byte[] bytes = new byte[readBuffer.remaining()];
					readBuffer.get(bytes);
					String body = new String(bytes, "UTF-8");
					System.out.println("Now is: "+body);
					this.stop=true;
				}else if(readBytes<0){
					key.cancel();
					sc.close();
				} else{
					//读到0字节
				}
			}
		}
	}

	private void doConnect() throws IOException{
		if(socketChannel.connect(new InetSocketAddress(host, port))){
			socketChannel.register(selector, SelectionKey.OP_READ);
			doWrite(socketChannel);
		}else{
			socketChannel.register(selector, SelectionKey.OP_CONNECT);
		}
	}
	
	private void doWrite(SocketChannel sc) throws IOException {
		byte[] req = "QUERY TIME ORDER".getBytes();
		ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
		writeBuffer.put(req);
		writeBuffer.flip();
		sc.write(writeBuffer);
		if(!writeBuffer.hasRemaining())
			System.out.println("Send order 2 server succeed.");
	}
	
}